An outbreak of carbapenem-resistant Escherichia coli producing the New Delhi metallo-beta-lactamase among 39 patients in one hospital was linked to duodenoscope exposure, according to a report in JAMA.
Researchers from CDC’s Division of Healthcare Quality Promotion evaluated risk factors for NDM-producing carbapenem-resistant Enterobacteriaceae (CRE) among cases identified from January to July 2013. The field investigation identified nine cases, eight of which had received treatment at the hospital.
Findings from an epidemiological analysis indicated no overlap of patient rooms or wards, but six of the eight cases had undergone endoscopic retrograde cholangiopancreatography (ERCP). Four patients had been exposed to duodenoscope A only, one had been exposed to duodenoscope B only and one had been exposed to both. Among the three patients who did not undergo this procedure, all were linked to a known case or had been admitted to the hospital during the outbreak.
In a case-control analysis of the eight hospital-treated and 27 control patients, cases were significantly associated with a history of ERCP. An infection prevention assessment revealed no breaches in duodenoscope reprocessing at the hospital. All procedural steps were followed correctly, and approved products were used.
Two additional cases were identified from clinical cultures in September 2013. Both had been exposed to a third duodenoscope only (duodenoscope C). The facility contacted the 226 surviving patients exposed to any duodenoscope in the hospital, and 102 returned for screening. An additional 27 case patients were identified, all of whom were exposed to at least one of the three duodenoscopes. A final patient was identified after screening roommates of the known case patients.
The hospital changed its duodenoscope reprocessing procedure to gas sterilization with ethylene oxide, and no new cases of duodenoscope-associated NDM-producing E. coli have been identified.
“Bacterial contamination of duodenoscopes appeared to persist despite the absence of recognized reprocessing lapses,” the researchers wrote. “Facilities should be aware of the potential for transmission of antimicrobial-resistant organisms via this route and should conduct regular reviews of their duodenoscope reprocessing procedures to ensure optimal manual cleaning and disinfection.”
Disclosure: The researchers report no relevant financial disclosures.